Abstract: A moisture detection sensor self-adhesive tape is used in a building structure to detect moisture penetration and includes a substrate of dielectric, hydrophobic material. Two elongate, parallel, conductors are secured to the top surface of the substrate and a protective layer of non-hygroscopic, water pervious material secured to the to the top surface of the substrate, over the conductors. A pressure sensitive mounting adhesive is placed on a bottom surface of the substrate and covered with a release sheet. The sensor may include moisture probes adapted to penetrate the protective layer, the respective conductors and the substrate and to extend into a building component to which the substrate has been adhered. The preferred moisture probe is a U-shaped metal staple configured to be driven in by a conventional power stapler.